The invention relates to shields for use with row-crop cultivators.
In the cultivation of row crops, farmers often encounter trash from preceding crops, grasses, large weeds, and difficult soil conditions including rocks and other heavy debris embedded in the ground. Such conditions are particularly common where ridge-till, no-till or minimum till planting procedures are employed. Rocks or other debris encountered during such cultivation can damage the equipment. In addition, when ridges are being built, slabs of soil, rocks or debris flowing from the ridger can damage the crop plants being cultivated.
Numerous shields in the form of attachments to cultivators have been developed for the purpose of protecting row crops during cultivation and/or ridge building. Such shields are designed to be located between the cultivating tools and the crop plants to prevent flying debris from damaging the plants.
For cultivating small plants, rolling, tunnel or tent shields affixed to a tool bar can be used. The latter shields are in the form of arched pieces of metal that completely cover the plants as the cultivation tools move along between the crop rows. Tunnel shields can be adjusted for height and for placement in relation to cutting disc hillers and sweeps.
For taller plants, substantially planar vertical shields are used that typically are formed of sheet metal. With some shields, a portion is bent away from the crop rows at the front of the shield to gather the plant leaves without damage thereto and to further deflect debris. Such shields can be attached to one or more brackets which in turn are attached to a horizontal arm mounted to the main tool bar of the cultivator implement. The shield can be moved vertically by adjusting the brackets. Also, the horizontal arm can be bolted solidly in place or allowed to pivot and float upwardly, for instance with a spring arrangement, to allow movement over rocks and trash. Some shields can be pivoted upwardly, completely out of the way of the crop plants.
The planar shields are positioned substantially parallel to one another on opposing sides of the cultivator equipment. In some instances, the mounting apparatus for the shields is located directly above the respective crop row, joining a pair of shields disposed on opposite sides of the same row. An example is shown in U.S. Pat. No. 4,552,225 for Cultivation Shield Attachment issued on Nov. 12, 1985. As is apparent, such an arrangement can interfere with tall crop plants. Other shields, known as open top shields, are paired such that they are joined over the cultivating equipment, i.e., each joined pair connects a shield on each side of a cultivator unit or gang. This arrangement eliminates obstructions in the space over the crop rows due to the shields or shield support mechanism.
In spite of the recent advances with shields, problems are still encountered when soil, rocks and other debris hit the shields; the shields are not rigid and can be deflected into the crop plants, thereby causing crop damage. In particular, with the use of single vertical mounting brackets, each shield may rotate about the vertical bracket when subjected to the impact of debris at either of its end portions, deflecting the outer ends of the shield into the crop row. The shield also may rotate laterally about the mounting arm causing its lower or base portion to swing into the crop row. Even with the use of two parallel vertical brackets, while rotation about the two brackets is reduced the shield still may swing outwardly about the mounting arm. A second problem arises when the shields contact substantial rocks or other heavy debris embedded in the ground. The impact of such rocks or debris on the shield's leading edge can cause damage to the shield assembly or divert the shield into the crop, even where spring arrangements are employed.
It is highly desirable to provide a shield assembly with stabilized shields that provide optimum protection to the plants being cultivated. It is also desirable for the shield assembly to readily retract to the extent necessary to overcome the impact of debris or rocks it has encountered, but it must be kept in mind that too much vertical movement of the shield will expose the plants to the soil and debris being thrown sideways by the cultivator. It is also desirable to provide such a shield assembly that is mounted over the cultivator implements so that there is no interference with tall plants in the crop rows being cultivated.
It is therefore an object of this invention to provide an improved shield assembly which operates to provide optimum protection to crops without resulting in damage to the shield assembly.
Another object of this invention is to provide a shield combination which can withstand the impact of flying debris from a cultivator and not deflect into the crop rows.
It is a further object of this invention to provide a shield assembly which can retract generally horizontally, about an axis perpendicular to the shields, to avoid sustaining damage from embedded or substantial rocks but which will remain close to the ground to protect the crop plants.
It is yet another object to provide a shield assembly that satisfies the preceding objects which at the same time maintains clearance for tall crop plants.
Other objects and advantages of this invention will become apparent upon reading the following detailed description and appended claims and upon reference to the accompanying drawings.